fix: The max_tokens parameter in the model configuration is invalid

backend/apps/ai_model/openai/llm.py

@@ -1,5 +1,5 @@
 from collections.abc import Iterator, Mapping
-from typing import Any, cast
+from typing import Any, Optional, cast
 
 from langchain_core.language_models import LanguageModelInput
 from langchain_core.messages import (
@@ -84,6 +84,26 @@ def _convert_delta_to_message_chunk(
 
 
 class BaseChatOpenAI(ChatOpenAI):
+    @property
+    def _default_params(self) -> dict[str, Any]:
+        max_tokens = self.max_tokens
+        params = super()._default_params
+        if max_tokens:
+            params["max_tokens"] = max_tokens
+        return params
+    
+    def _get_request_payload(
+        self,
+        input_: LanguageModelInput,
+        *,
+        stop: Optional[list[str]] = None,
+        **kwargs: Any,
+    ) -> dict:
+        max_tokens = self.max_tokens
+        payload = super()._get_request_payload(input_, stop=stop, **kwargs)
+        if max_tokens:
+            payload["max_tokens"] = max_tokens
+        return payload
     usage_metadata: dict = {}
 
     # custom_get_token_ids = custom_get_token_ids